This invention is directed towards aerators. More particularly, the invention relates to a core type aerator configured to eliminate damage around a top of a hole made through insertion and removal of tines extending from the aerator into the ground during aeration.
It is common practice in the treating of turf, such as on golf courses and similar groomed lawn areas, to aerate the turf. Aeration is performed by forming a pattern of generally cylindrical shaped holes in the turf that enable moisture, fertilizers, and the like, to more readily reach and stimulate root growth, which leads to a heartier turf.
Through aeration air and water, together with fertilizer and top dressing, are permitted to penetrate the turf after aeration with resultant improvement in the depth of the root structure of the grasses producing an end result of a luxurious grass mat. One type of aeration merely pokes holes into turf with spikes, or the like. A more productive type of aeration occurs where a plug or cylinder of turf or ground is cut and removed from the turf, which is contrasted with the aerification through spiking since in the latter spikes are forced into the turf. This actually compacts the soil around the hole in the ground, thereby impeding moisture penetration into the turf or ground. In the former method, the aeration holes are conventionally formed by an apparatus, termed an aerator, which includes a plurality of coring tines operative to penetrate the soil in a manner to remove generally cylindrical cores or plugs of turf.
In a core-type aerator, stationary tines are mounted in generally radial relation about a tine wheel that rotates about an axis transverse to the direction of movement of the aerator. The tines are conventionally mounted in circumferentially spaced rows, such that the tines sequentially penetrate the soil as the tine wheel rotates to create a pattern of aeration holes. Aerators of the rotary tine wheel type are generally further classified into two categories: towed or driven type aerators. Towed type aerators have tine wheels supported for substantially free rotation about their longitudinal axes and are caused to rotate in response to towing of the aerator by a tractor or the like through a draw bar or three-point hitch arrangement. On the other hand, driven tine wheel type aerators have a tine wheel that has a positive driven relation with motor means or the like carried by the aerator. The driven tine wheel type aerators are operative when energized to cause the tine wheel to rotate so as to propel the aerator, while simultaneously effecting tine penetration to aerate the underlying turf. Significant differences exist between these two types of aerators that influence the specific tine geometry best suited for each type aerator.
For example, the forces delivered to the soil through the tines, termed the tine penetration forces, are different for towed and driven tine wheel aerators. This difference dictates the need for different tine angles between towed and driven tine wheels. Tine angle is the angular relation between the longitudinal axis of the turf penetrating end of the tine and a radius extending from the rotational axis of the tine wheel and generally intersecting the point at which the tine extends from the tine wheel periphery. This relation may also be termed the tine orientation geometry.
For a towed type tine wheel, two forces must be supported by the soil: a component of the draw bar pulling force, and the weight of the machine. A driven type tine wheel also has two forces that must be supported by the soil: the weight of the machine and the resultant force of the driving torque acting on the tine wheel. This resultant driving torque force is generally larger than the draw bar component force of a towed type tine wheel so that the weight required to effect the same aerating core depth is generally less for a driven tine wheel type aerator. The differences in tine penetration forces between towed and driven tine wheel type aerators also change the instant center of rotation, or true rolling radius, of the tine wheel; specifically, the instant center of the driven tine wheel tends to be deeper in the soil than for a towed type tine wheel. This difference necessitates different tine angles or tine orientation geometry for the driven type tine wheels to provide optimum aerating performance. Based on the different angles needed tines enter the ground in non-vertical positions causing unwanted damage to turf surrounding the opening in the ground made during the penetration.
A desirable objective of rotary tine wheel type aerators, and particularly aerators employed to aerate golf course greens or other areas where relatively even surfaces are critical, is to form the aerification holes with minimum disturbance or lifting of the turf peripherally about the hole openings. Although several aerators have been developed for this purpose through angular arrangement or multiple tine arrangements, they still have major drawbacks. One is that although some hole opening disturbance is eliminated, other problems occur, such as channels being formed between hole openings based on the stationary nature of the tines.
Therefore, a need exists for a plug aerator that does not damage the ground around a hole or the ground in between the holes, where the holes are made during aeration.
According to the present invention, a method and apparatus for core extracting plug aerator comprises a main frame, a draw bar coupled to the main frame and configured to couple a motorized device to the main frame, and pivoting side supports coupled to the main frame, wherein the side supports pivot between and are secured in a moving position and an aerating position. The plug aerator further comprises rotating wheels coupled to the side supports and a longitudinal support system coupled to the main frame, the longitudinal support system comprises a plugger system comprising articulating tines.
A main advantage of the plug aerator according to a preferred embodiment of the present invention is that aeration holes are formed preferably without disturbing, or with minimum disturbance, of either the opening of the hole or the ground between holes based on the articulation of the tines.